How to subpoena sheriffs records?

My ex and her boyfriend got into an altercation where the Sheriifs were called out, apparently this occurs regularly and this was the first time law enforcement was called. My daughter stays there 50% of the time and we are in the beginnings of a child custody battle, I have concerns about the childs safety at this location and have attempted to acquire these records as I am pro per in this matter yet was told they would have to be subpoenaed. The matter is in California and I am looking for advice on how to go about this, forms, hearings, etc. Thanks for any advice...